Conveyer idler



Nov. 20, 1951 H. T. SHANK CONVEYER IDLER Filed April so, 1948 Q Q-Q NN MN Patented Nov. 20, 1951 U N I TED E S OFF 1 C CONVEYER IDLER Harvey'lillmamShank, Toronto, Ontario, Canada Application Apr'ilt30, 1948, .SerialjNo; 24,211

4 ,Claims:1:.z(Cl. 198E202) 1 This invention relatesto atroughing idler for a belt conveyor of the type which employs spring coils as idler rollers and constitutes a continuation-in-part of my co-pending United States application Serial No; 787,293 and now Patent No. That applica'-:

2,555 765 granteddune 5, 1951; tion was directed-to a troughing idler having'a single coil spring idler roller which was formedfrom its centre, in a right-'handedcbil towards one end and in a left-handed coil towards the other end so that in operation the right-handed and left-handed portions of the idler roller exert' equal and opposite side thrust forces on the .con-- veyor belt to prevent it from riding' offm The embodiment of the invention disclosed in application Serial bio-787,293 is very satisfactory in operation.

makes it possible to predeterminethe'angle of assured trough.

It is then an object of this invention-to provide a coil idler having coilidler rollers which will not force the belt from the idler.

It is a further object of the invention to provide a troughing idler having :the abovecharacteristics in which it is possible to predetermine.

the amount of assured trough.-

It is a further object of the invention to cone struct a conveyor idler employing coil idler-roll ers which is easy and cheap to manufacturer- It is a still further-object" of the invention'to provide a troughing idler having the above characteristics and means in connection therewith for taking up spring fatigue.-

With these and other objectsin view, a conveyor idler according to the present invention comprises a series of idler rollers and means-for rotatably mounting the idler rollers withytheir longitudinal axe in a common vertical plane to support a conveyor belt. The outside two of said series of rollers are spring coils, of similar pitch, one being coiled to the right and the other being coiled to the left. The invention will, of course, be clearly understood after reference to the following detailed specification read in conjunction with the drawings.

In the drawings,

Figure 1 shows a front view partly in section of one embodiment of the invention.

Figure 2 shows a front view of a further embodiment of the invention.

Figure 3 is a partial end view showing the pivotal mounting of the idler rollers in an end support.

Referring to the drawings, and at first to Fig- This present embodiment of the invention however, is cheaper to construct-and ure '1-;=letter A-indicatesgenerally a conveyor idler according to --this-in-vention.- It comprises a base- I'll having rigidendsupports I! and i2 and "centre support 13 rigidly'secured thereto. Numerals l4 and =l5-indicate'coi1 spring idlers which-are rotatably mounted between the standards I I, I2 and I3 with their vertical axes troughedin a common vertical ;plane to support the conveyor belt'ltag-" bymeans of thecups it, extending shank portions H and pinslt.

Thecoilsld and iii are equal in pitch and arecoile'd-in opposite directionsfromtheir innerends; The coil I4 is coiled 'to the right from its inner end and-the coil-+5 is coiled to the "left from -its innerend: 1 In operation it will be ap parent that these-coils will exert equal but op posite-side thrust forces'on a conveyor belt as it passes over them.

Thecups 16 project into the open'ends of .the coil springs Hiandi5 and are rigidly secured therein-=by means of pins 19 which pass through" a'tur-n or-the coil 'spring and enter into a' suitably bored hole in the cups. Thecups'preferably' have undulating'suriaces as indicated at 23 to accommodate and separate adjacent turns of the coil-springs;

'Ihei-coils are securedto the mounting posts Fiji-2 and 1-3 by means'of the shanks ll. These: shanks are pivotallymounted adjacent one-of their ends in the forked ends of the supports ii, I 2 or 13 by means of suitable pins it. At their opposite ends the shanks are designed to thread ably-receive nuts 22 "whichin operation bearagainst the ball bearings 2d to permit th cups: and *theirconnected roller 'idlers to rotate rela'' tive to the shanks.- The nuts 22 are retained in position by means of suitable'locking pins '23 designed to pass through the 'nuts and shanks;

The above description-of the mounting for the coil idlers relates specifically to the outer mountings. The centre mountings however, are similar and it is not thought that it is necessary t refer to them by numerals.

In the embodiment of the invention shown in Figure l the outer supports H and 12 are higher than the centre support I 3. The height of these supports can be designed to support the rollers l4 and 15 with their longitudinal axes in a common vertical plane to support a conveyor belt with a predetermined amount of trough. The amount of predetermined trough will depend on the goods to be conveyed. It would, for example, be greater for light materials than heavy materials because light materials would not cause the coils to trough as much as heavy ones. The

3 outer standards II and I2 are adjustable in the horizontal slots 25 in the base member 26 to adjust the tension on the spring coils. When the desired tension is achieved the standards ll and 12 are tightened in position by means of bolts 26.

The operation of the idler will be apparent. The bearing cups l6 rotate with the coils to which they are secured and the bearings 24 permit relative rotation between the cups and the shanks [7. In this connection, the outer race 24a of the bearing bears against the shoulder Mia and the inner race 24b of the bearing bears against the nut 23 while the ball bearings 240 permit free relative rotation between the two. The shanks ll, of course, are free to pivot vertically about the pins l8.

Considering the operation of the unit as a whole the conveyor belt [a movesout of the page to cause the rollers to rotate in a clockwise direction when viewed from the left side, that is, from the side of the end support H in Figure 1. It will be apparent that the spiral coil idlers l4 and 15 will tend to urge the respective halves of the conveyor belt 15a which they support towards the centre. The urging forces, however, are equal and as a result, the conveyor belt will remain centrally located on the idler.

Figure 2 shows an alternative embodiment of this invention. In that figure, I show three idler rollers 27, 28 and 29 rotatably mounted in supports 30, 3!, 32 and 33 with their longitudinal axes in a common vertical plane and troughed to support a conveyor belt. The centre roller 27 is solid and the outer rollers 28 and 29 comprise spring coils. The outer roller 28 is coiled from its inner end to the right and the roller 26 is coiled from its inner end to the left. The pitch of the two coils is similar.

The pitch of the idler rollers is preferably smaller adjacent their inner ends as indicated at 34 in Figure 2. This is to support the heavier weights which will be carried adjacent the centre of the conveyor.

From the above it will be apparent that I have disclosed a conveyor idler which accomplishes the objects of this invention. The similar coil spring idlers employed exert equal and opposite side thrust forces on the conveyor belt to retain it in its proper postion on the conveyor idler. The separate coil spring idlers are easy and cheap to manufacture and make it possible to form an idler with a predetermined amount of trough. Other forms of the invention than those shown will, of course, be apparent to those skilled in the art of conveyor idlers. It is, therefore, intended that the specification should not be read in a limiting sense .except for the limitations expressed in the. following claims.

What I claim as my invention is:

1. In a troughing conveyor idler, a series of idler rollers, rotatably mounted with their longitudinal axes in a common vertical plane to support a conveyor belt, the outside two of said idler rollers being spring coils and carrying mounting cup means at each of their free ends, one of the coils being coiled to the right and the other being coiled to the left, the pitch of said coils being similar and smaller adjacent their inner ends than their outer ends.

2. In a troughing idler, a series of idler rollers, rotatably mounted with their longitudinal axes troughed in a common vertical plane to support a a conveyor belt, the outside two of said idler rollers being spring coils and carrying mounting cup means at each of their free ends, one of the coils being coiled to the right and the other being coiled to the left, the pitch of said coils being similar and smaller adjacent their inner ends than their outer ends.

3. In a troughing conveyor idler, two spring coil idler rollers, rotatably mounted with their longitudinal axes troughed in a common vertical plane to support a conveyor belt, one of said coils being coiled to the right and the other being coiled to the left, each of said rollers having mounting means in each of its ends, the pitch of said rollers being similar and smaller adjacent their inner ends.

4. In a troughing conveyor idler, two spring coil idler rollers, rotatably mounted with their longitudinal axes troughed in a common vertical plane to support a conveyor belt, the inner ends of said coil idlers being at a common level and at a predetermined height below the outer ends of said coil idler rollers, one of said rollers being coiled to the right and the other being coiled to the left, each of said coils having mounting cup means at each of its free ends, the pitch of said coils being similar and smaller and adjacent their inner ends.

HARVEY TILLMAN SHANK.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 857,610 Dull June 25, 1907 857,772 Thomas June 25, 1907 1,980,777 Zollinger Nov. 13, 1934 2,391,178 McKnight Dec. 18, 1945 2,393,471 Johnson Jan. 22, 1946 FOREIGN PATENTS Number Country Date 418,677 Great Britain Oct. 29, 1934 672,218 Germany Feb. 22, 1939 

